A form of food poisoning secondary to histamine toxicity, also known as scombroid poisoning, is sometimes confused with an allergic reaction to fish. Some kinds of fish contain naturally high levels of the chemical histidine. This chemical can be converted to histamine by bacteria. Histamine is the chemical which triggers allergy symptoms in an allergic reaction. So, if a person eats fish that has a high level of histamine, the response may resemble an allergic reaction to that food.
Certain kinds of fish, tuna, mackerel, mahi mahi, anchovy, herring, bluefish, amberjack and marlin are more prone to cause histamine toxicity.
Most commonly the cause of acute histamine toxicity is the result of inadequate refrigeration or spoiled fish. This causes an overgrowth of bacteria which converts histidine to high levels of histamine.
Individuals who have unusually low levels of the enzyme diamine oxidase may be more susceptible to histamine toxicity.
Symptoms & Diagnosis
Scombroid poisoning symptoms typically begin within 5 to 30 minutes after eating spoiled fish, although there are cases when symptoms are delayed for as long as two hours.
These symptoms may include:
- Burning in the mouth
- Flushing of the face and body
- Faintness, sometimes with blurring vision
- Abdominal cramps
- Wheezing or other breathing problems
- Swelling of the face and tongue
Symptoms typically last a few hours or a day. In rare cases, symptoms can persist for a few days.
Diagnosing the condition is often based on circumstance. For instance, outbreaks of typical symptoms affecting several people who have eaten the same contaminated product most likely indicates histamine toxicity. If it happens in individual cases it is best to consult an allergist / immunologist to determine whether a food allergy exists.
Treatment & Management
Treatment for histamine toxicity depends on the severity of the symptoms. In mild cases, symptoms tend to go away in a short period of time without medication. Sometimes antihistamines can help.
In severe cases, a trip to a hospital emergency room is necessary for care with IV fluids, oxygen or other medications and treatments.